Enhanced cellular responses to titanium coating with hierarchical hybrid structure.

In this work, nano/micro hierarchical hybrid structured surface was prepared by fabricating a titania nanotube layer in plasma sprayed porous titanium coating (TC). In vitro human marrow stem cells (hMSCs) were employed for the evaluation of the biological properties of the anodized titanium coating with a hierarchical structure (HSTC). Significantly higher cell adhesion quantity (about 30% more) was found on the HSTC than that on the as-sprayed TC. The expressions of osteocalcin (OC) and osteopontin (OPN) for the HSTC were also detected to be about twice as high as those on the as-sprayed TC. The enhanced cell responses on the HSTC were explained by the improved protein adhesion resulted from the increased surface area and surface energy. Combining the advantages in the mechanical fixation and long-term stability of the plasma sprayed porous TC, the HSTC with a hierarchical structure may be a good candidate for hard tissue replacements, especially for load-bearing implants.